Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1100 insertions, 0 deletions

diff --git a/net/batman-adv/bat_v_ogm.c b/net/batman-adv/bat_v_ogm.c
new file mode 100644
index 000000000..c451694fd
--- /dev/null
+++ b/net/batman-adv/bat_v_ogm.c
@@ -0,0 +1,1100 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (C) 2013-2020  B.A.T.M.A.N. contributors:
+ *
+ * Antonio Quartulli
+ */
+
+#include "bat_v_ogm.h"
+#include "main.h"
+
+#include <linux/atomic.h>
+#include <linux/byteorder/generic.h>
+#include <linux/errno.h>
+#include <linux/etherdevice.h>
+#include <linux/gfp.h>
+#include <linux/if_ether.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/list.h>
+#include <linux/lockdep.h>
+#include <linux/mutex.h>
+#include <linux/netdevice.h>
+#include <linux/prandom.h>
+#include <linux/random.h>
+#include <linux/rculist.h>
+#include <linux/rcupdate.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/stddef.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <uapi/linux/batadv_packet.h>
+
+#include "bat_algo.h"
+#include "hard-interface.h"
+#include "hash.h"
+#include "log.h"
+#include "originator.h"
+#include "routing.h"
+#include "send.h"
+#include "translation-table.h"
+#include "tvlv.h"
+
+/**
+ * batadv_v_ogm_orig_get() - retrieve and possibly create an originator node
+ * @bat_priv: the bat priv with all the soft interface information
+ * @addr: the address of the originator
+ *
+ * Return: the orig_node corresponding to the specified address. If such an
+ * object does not exist, it is allocated here. In case of allocation failure
+ * returns NULL.
+ */
+struct batadv_orig_node *batadv_v_ogm_orig_get(struct batadv_priv *bat_priv,
+					       const u8 *addr)
+{
+	struct batadv_orig_node *orig_node;
+	int hash_added;
+
+	orig_node = batadv_orig_hash_find(bat_priv, addr);
+	if (orig_node)
+		return orig_node;
+
+	orig_node = batadv_orig_node_new(bat_priv, addr);
+	if (!orig_node)
+		return NULL;
+
+	kref_get(&orig_node->refcount);
+	hash_added = batadv_hash_add(bat_priv->orig_hash, batadv_compare_orig,
+				     batadv_choose_orig, orig_node,
+				     &orig_node->hash_entry);
+	if (hash_added != 0) {
+		/* remove refcnt for newly created orig_node and hash entry */
+		batadv_orig_node_put(orig_node);
+		batadv_orig_node_put(orig_node);
+		orig_node = NULL;
+	}
+
+	return orig_node;
+}
+
+/**
+ * batadv_v_ogm_start_queue_timer() - restart the OGM aggregation timer
+ * @hard_iface: the interface to use to send the OGM
+ */
+static void batadv_v_ogm_start_queue_timer(struct batadv_hard_iface *hard_iface)
+{
+	unsigned int msecs = BATADV_MAX_AGGREGATION_MS * 1000;
+
+	/* msecs * [0.9, 1.1] */
+	msecs += prandom_u32_max(msecs / 5) - (msecs / 10);
+	queue_delayed_work(batadv_event_workqueue, &hard_iface->bat_v.aggr_wq,
+			   msecs_to_jiffies(msecs / 1000));
+}
+
+/**
+ * batadv_v_ogm_start_timer() - restart the OGM sending timer
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_v_ogm_start_timer(struct batadv_priv *bat_priv)
+{
+	unsigned long msecs;
+	/* this function may be invoked in different contexts (ogm rescheduling
+	 * or hard_iface activation), but the work timer should not be reset
+	 */
+	if (delayed_work_pending(&bat_priv->bat_v.ogm_wq))
+		return;
+
+	msecs = atomic_read(&bat_priv->orig_interval) - BATADV_JITTER;
+	msecs += prandom_u32_max(2 * BATADV_JITTER);
+	queue_delayed_work(batadv_event_workqueue, &bat_priv->bat_v.ogm_wq,
+			   msecs_to_jiffies(msecs));
+}
+
+/**
+ * batadv_v_ogm_send_to_if() - send a batman ogm using a given interface
+ * @skb: the OGM to send
+ * @hard_iface: the interface to use to send the OGM
+ */
+static void batadv_v_ogm_send_to_if(struct sk_buff *skb,
+				    struct batadv_hard_iface *hard_iface)
+{
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+
+	if (hard_iface->if_status != BATADV_IF_ACTIVE) {
+		kfree_skb(skb);
+		return;
+	}
+
+	batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_TX);
+	batadv_add_counter(bat_priv, BATADV_CNT_MGMT_TX_BYTES,
+			   skb->len + ETH_HLEN);
+
+	batadv_send_broadcast_skb(skb, hard_iface);
+}
+
+/**
+ * batadv_v_ogm_len() - OGMv2 packet length
+ * @skb: the OGM to check
+ *
+ * Return: Length of the given OGMv2 packet, including tvlv length, excluding
+ * ethernet header length.
+ */
+static unsigned int batadv_v_ogm_len(struct sk_buff *skb)
+{
+	struct batadv_ogm2_packet *ogm_packet;
+
+	ogm_packet = (struct batadv_ogm2_packet *)skb->data;
+	return BATADV_OGM2_HLEN + ntohs(ogm_packet->tvlv_len);
+}
+
+/**
+ * batadv_v_ogm_queue_left() - check if given OGM still fits aggregation queue
+ * @skb: the OGM to check
+ * @hard_iface: the interface to use to send the OGM
+ *
+ * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
+ *
+ * Return: True, if the given OGMv2 packet still fits, false otherwise.
+ */
+static bool batadv_v_ogm_queue_left(struct sk_buff *skb,
+				    struct batadv_hard_iface *hard_iface)
+{
+	unsigned int max = min_t(unsigned int, hard_iface->net_dev->mtu,
+				 BATADV_MAX_AGGREGATION_BYTES);
+	unsigned int ogm_len = batadv_v_ogm_len(skb);
+
+	lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
+
+	return hard_iface->bat_v.aggr_len + ogm_len <= max;
+}
+
+/**
+ * batadv_v_ogm_aggr_list_free - free all elements in an aggregation queue
+ * @hard_iface: the interface holding the aggregation queue
+ *
+ * Empties the OGMv2 aggregation queue and frees all the skbs it contains.
+ *
+ * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
+ */
+static void batadv_v_ogm_aggr_list_free(struct batadv_hard_iface *hard_iface)
+{
+	lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
+
+	__skb_queue_purge(&hard_iface->bat_v.aggr_list);
+	hard_iface->bat_v.aggr_len = 0;
+}
+
+/**
+ * batadv_v_ogm_aggr_send() - flush & send aggregation queue
+ * @hard_iface: the interface with the aggregation queue to flush
+ *
+ * Aggregates all OGMv2 packets currently in the aggregation queue into a
+ * single OGMv2 packet and transmits this aggregate.
+ *
+ * The aggregation queue is empty after this call.
+ *
+ * Caller needs to hold the hard_iface->bat_v.aggr_list.lock.
+ */
+static void batadv_v_ogm_aggr_send(struct batadv_hard_iface *hard_iface)
+{
+	unsigned int aggr_len = hard_iface->bat_v.aggr_len;
+	struct sk_buff *skb_aggr;
+	unsigned int ogm_len;
+	struct sk_buff *skb;
+
+	lockdep_assert_held(&hard_iface->bat_v.aggr_list.lock);
+
+	if (!aggr_len)
+		return;
+
+	skb_aggr = dev_alloc_skb(aggr_len + ETH_HLEN + NET_IP_ALIGN);
+	if (!skb_aggr) {
+		batadv_v_ogm_aggr_list_free(hard_iface);
+		return;
+	}
+
+	skb_reserve(skb_aggr, ETH_HLEN + NET_IP_ALIGN);
+	skb_reset_network_header(skb_aggr);
+
+	while ((skb = __skb_dequeue(&hard_iface->bat_v.aggr_list))) {
+		hard_iface->bat_v.aggr_len -= batadv_v_ogm_len(skb);
+
+		ogm_len = batadv_v_ogm_len(skb);
+		skb_put_data(skb_aggr, skb->data, ogm_len);
+
+		consume_skb(skb);
+	}
+
+	batadv_v_ogm_send_to_if(skb_aggr, hard_iface);
+}
+
+/**
+ * batadv_v_ogm_queue_on_if() - queue a batman ogm on a given interface
+ * @skb: the OGM to queue
+ * @hard_iface: the interface to queue the OGM on
+ */
+static void batadv_v_ogm_queue_on_if(struct sk_buff *skb,
+				     struct batadv_hard_iface *hard_iface)
+{
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+
+	if (!atomic_read(&bat_priv->aggregated_ogms)) {
+		batadv_v_ogm_send_to_if(skb, hard_iface);
+		return;
+	}
+
+	spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
+	if (!batadv_v_ogm_queue_left(skb, hard_iface))
+		batadv_v_ogm_aggr_send(hard_iface);
+
+	hard_iface->bat_v.aggr_len += batadv_v_ogm_len(skb);
+	__skb_queue_tail(&hard_iface->bat_v.aggr_list, skb);
+	spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
+}
+
+/**
+ * batadv_v_ogm_send_softif() - periodic worker broadcasting the own OGM
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+static void batadv_v_ogm_send_softif(struct batadv_priv *bat_priv)
+{
+	struct batadv_hard_iface *hard_iface;
+	struct batadv_ogm2_packet *ogm_packet;
+	struct sk_buff *skb, *skb_tmp;
+	unsigned char *ogm_buff;
+	int ogm_buff_len;
+	u16 tvlv_len = 0;
+	int ret;
+
+	lockdep_assert_held(&bat_priv->bat_v.ogm_buff_mutex);
+
+	if (atomic_read(&bat_priv->mesh_state) == BATADV_MESH_DEACTIVATING)
+		goto out;
+
+	ogm_buff = bat_priv->bat_v.ogm_buff;
+	ogm_buff_len = bat_priv->bat_v.ogm_buff_len;
+	/* tt changes have to be committed before the tvlv data is
+	 * appended as it may alter the tt tvlv container
+	 */
+	batadv_tt_local_commit_changes(bat_priv);
+	tvlv_len = batadv_tvlv_container_ogm_append(bat_priv, &ogm_buff,
+						    &ogm_buff_len,
+						    BATADV_OGM2_HLEN);
+
+	bat_priv->bat_v.ogm_buff = ogm_buff;
+	bat_priv->bat_v.ogm_buff_len = ogm_buff_len;
+
+	skb = netdev_alloc_skb_ip_align(NULL, ETH_HLEN + ogm_buff_len);
+	if (!skb)
+		goto reschedule;
+
+	skb_reserve(skb, ETH_HLEN);
+	skb_put_data(skb, ogm_buff, ogm_buff_len);
+
+	ogm_packet = (struct batadv_ogm2_packet *)skb->data;
+	ogm_packet->seqno = htonl(atomic_read(&bat_priv->bat_v.ogm_seqno));
+	atomic_inc(&bat_priv->bat_v.ogm_seqno);
+	ogm_packet->tvlv_len = htons(tvlv_len);
+
+	/* broadcast on every interface */
+	rcu_read_lock();
+	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+		if (hard_iface->soft_iface != bat_priv->soft_iface)
+			continue;
+
+		if (!kref_get_unless_zero(&hard_iface->refcount))
+			continue;
+
+		ret = batadv_hardif_no_broadcast(hard_iface, NULL, NULL);
+		if (ret) {
+			char *type;
+
+			switch (ret) {
+			case BATADV_HARDIF_BCAST_NORECIPIENT:
+				type = "no neighbor";
+				break;
+			case BATADV_HARDIF_BCAST_DUPFWD:
+				type = "single neighbor is source";
+				break;
+			case BATADV_HARDIF_BCAST_DUPORIG:
+				type = "single neighbor is originator";
+				break;
+			default:
+				type = "unknown";
+			}
+
+			batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 from ourselves on %s suppressed: %s\n",
+				   hard_iface->net_dev->name, type);
+
+			batadv_hardif_put(hard_iface);
+			continue;
+		}
+
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Sending own OGM2 packet (originator %pM, seqno %u, throughput %u, TTL %d) on interface %s [%pM]\n",
+			   ogm_packet->orig, ntohl(ogm_packet->seqno),
+			   ntohl(ogm_packet->throughput), ogm_packet->ttl,
+			   hard_iface->net_dev->name,
+			   hard_iface->net_dev->dev_addr);
+
+		/* this skb gets consumed by batadv_v_ogm_send_to_if() */
+		skb_tmp = skb_clone(skb, GFP_ATOMIC);
+		if (!skb_tmp) {
+			batadv_hardif_put(hard_iface);
+			break;
+		}
+
+		batadv_v_ogm_queue_on_if(skb_tmp, hard_iface);
+		batadv_hardif_put(hard_iface);
+	}
+	rcu_read_unlock();
+
+	consume_skb(skb);
+
+reschedule:
+	batadv_v_ogm_start_timer(bat_priv);
+out:
+	return;
+}
+
+/**
+ * batadv_v_ogm_send() - periodic worker broadcasting the own OGM
+ * @work: work queue item
+ */
+static void batadv_v_ogm_send(struct work_struct *work)
+{
+	struct batadv_priv_bat_v *bat_v;
+	struct batadv_priv *bat_priv;
+
+	bat_v = container_of(work, struct batadv_priv_bat_v, ogm_wq.work);
+	bat_priv = container_of(bat_v, struct batadv_priv, bat_v);
+
+	mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
+	batadv_v_ogm_send_softif(bat_priv);
+	mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
+}
+
+/**
+ * batadv_v_ogm_aggr_work() - OGM queue periodic task per interface
+ * @work: work queue item
+ *
+ * Emits aggregated OGM messages in regular intervals.
+ */
+void batadv_v_ogm_aggr_work(struct work_struct *work)
+{
+	struct batadv_hard_iface_bat_v *batv;
+	struct batadv_hard_iface *hard_iface;
+
+	batv = container_of(work, struct batadv_hard_iface_bat_v, aggr_wq.work);
+	hard_iface = container_of(batv, struct batadv_hard_iface, bat_v);
+
+	spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
+	batadv_v_ogm_aggr_send(hard_iface);
+	spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
+
+	batadv_v_ogm_start_queue_timer(hard_iface);
+}
+
+/**
+ * batadv_v_ogm_iface_enable() - prepare an interface for B.A.T.M.A.N. V
+ * @hard_iface: the interface to prepare
+ *
+ * Takes care of scheduling its own OGM sending routine for this interface.
+ *
+ * Return: 0 on success or a negative error code otherwise
+ */
+int batadv_v_ogm_iface_enable(struct batadv_hard_iface *hard_iface)
+{
+	struct batadv_priv *bat_priv = netdev_priv(hard_iface->soft_iface);
+
+	batadv_v_ogm_start_queue_timer(hard_iface);
+	batadv_v_ogm_start_timer(bat_priv);
+
+	return 0;
+}
+
+/**
+ * batadv_v_ogm_iface_disable() - release OGM interface private resources
+ * @hard_iface: interface for which the resources have to be released
+ */
+void batadv_v_ogm_iface_disable(struct batadv_hard_iface *hard_iface)
+{
+	cancel_delayed_work_sync(&hard_iface->bat_v.aggr_wq);
+
+	spin_lock_bh(&hard_iface->bat_v.aggr_list.lock);
+	batadv_v_ogm_aggr_list_free(hard_iface);
+	spin_unlock_bh(&hard_iface->bat_v.aggr_list.lock);
+}
+
+/**
+ * batadv_v_ogm_primary_iface_set() - set a new primary interface
+ * @primary_iface: the new primary interface
+ */
+void batadv_v_ogm_primary_iface_set(struct batadv_hard_iface *primary_iface)
+{
+	struct batadv_priv *bat_priv = netdev_priv(primary_iface->soft_iface);
+	struct batadv_ogm2_packet *ogm_packet;
+
+	mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
+	if (!bat_priv->bat_v.ogm_buff)
+		goto unlock;
+
+	ogm_packet = (struct batadv_ogm2_packet *)bat_priv->bat_v.ogm_buff;
+	ether_addr_copy(ogm_packet->orig, primary_iface->net_dev->dev_addr);
+
+unlock:
+	mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
+}
+
+/**
+ * batadv_v_forward_penalty() - apply a penalty to the throughput metric
+ *  forwarded with B.A.T.M.A.N. V OGMs
+ * @bat_priv: the bat priv with all the soft interface information
+ * @if_incoming: the interface where the OGM has been received
+ * @if_outgoing: the interface where the OGM has to be forwarded to
+ * @throughput: the current throughput
+ *
+ * Apply a penalty on the current throughput metric value based on the
+ * characteristic of the interface where the OGM has been received.
+ *
+ * Initially the per hardif hop penalty is applied to the throughput. After
+ * that the return value is then computed as follows:
+ * - throughput * 50%          if the incoming and outgoing interface are the
+ *                             same WiFi interface and the throughput is above
+ *                             1MBit/s
+ * - throughput                if the outgoing interface is the default
+ *                             interface (i.e. this OGM is processed for the
+ *                             internal table and not forwarded)
+ * - throughput * node hop penalty  otherwise
+ *
+ * Return: the penalised throughput metric.
+ */
+static u32 batadv_v_forward_penalty(struct batadv_priv *bat_priv,
+				    struct batadv_hard_iface *if_incoming,
+				    struct batadv_hard_iface *if_outgoing,
+				    u32 throughput)
+{
+	int if_hop_penalty = atomic_read(&if_incoming->hop_penalty);
+	int hop_penalty = atomic_read(&bat_priv->hop_penalty);
+	int hop_penalty_max = BATADV_TQ_MAX_VALUE;
+
+	/* Apply per hardif hop penalty */
+	throughput = throughput * (hop_penalty_max - if_hop_penalty) /
+		     hop_penalty_max;
+
+	/* Don't apply hop penalty in default originator table. */
+	if (if_outgoing == BATADV_IF_DEFAULT)
+		return throughput;
+
+	/* Forwarding on the same WiFi interface cuts the throughput in half
+	 * due to the store & forward characteristics of WIFI.
+	 * Very low throughput values are the exception.
+	 */
+	if (throughput > 10 &&
+	    if_incoming == if_outgoing &&
+	    !(if_incoming->bat_v.flags & BATADV_FULL_DUPLEX))
+		return throughput / 2;
+
+	/* hop penalty of 255 equals 100% */
+	return throughput * (hop_penalty_max - hop_penalty) / hop_penalty_max;
+}
+
+/**
+ * batadv_v_ogm_forward() - check conditions and forward an OGM to the given
+ *  outgoing interface
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ogm_received: previously received OGM to be forwarded
+ * @orig_node: the originator which has been updated
+ * @neigh_node: the neigh_node through with the OGM has been received
+ * @if_incoming: the interface on which this OGM was received on
+ * @if_outgoing: the interface to which the OGM has to be forwarded to
+ *
+ * Forward an OGM to an interface after having altered the throughput metric and
+ * the TTL value contained in it. The original OGM isn't modified.
+ */
+static void batadv_v_ogm_forward(struct batadv_priv *bat_priv,
+				 const struct batadv_ogm2_packet *ogm_received,
+				 struct batadv_orig_node *orig_node,
+				 struct batadv_neigh_node *neigh_node,
+				 struct batadv_hard_iface *if_incoming,
+				 struct batadv_hard_iface *if_outgoing)
+{
+	struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
+	struct batadv_orig_ifinfo *orig_ifinfo = NULL;
+	struct batadv_neigh_node *router = NULL;
+	struct batadv_ogm2_packet *ogm_forward;
+	unsigned char *skb_buff;
+	struct sk_buff *skb;
+	size_t packet_len;
+	u16 tvlv_len;
+
+	/* only forward for specific interfaces, not for the default one. */
+	if (if_outgoing == BATADV_IF_DEFAULT)
+		goto out;
+
+	orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
+	if (!orig_ifinfo)
+		goto out;
+
+	/* acquire possibly updated router */
+	router = batadv_orig_router_get(orig_node, if_outgoing);
+
+	/* strict rule: forward packets coming from the best next hop only */
+	if (neigh_node != router)
+		goto out;
+
+	/* don't forward the same seqno twice on one interface */
+	if (orig_ifinfo->last_seqno_forwarded == ntohl(ogm_received->seqno))
+		goto out;
+
+	orig_ifinfo->last_seqno_forwarded = ntohl(ogm_received->seqno);
+
+	if (ogm_received->ttl <= 1) {
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "ttl exceeded\n");
+		goto out;
+	}
+
+	neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
+	if (!neigh_ifinfo)
+		goto out;
+
+	tvlv_len = ntohs(ogm_received->tvlv_len);
+
+	packet_len = BATADV_OGM2_HLEN + tvlv_len;
+	skb = netdev_alloc_skb_ip_align(if_outgoing->net_dev,
+					ETH_HLEN + packet_len);
+	if (!skb)
+		goto out;
+
+	skb_reserve(skb, ETH_HLEN);
+	skb_buff = skb_put_data(skb, ogm_received, packet_len);
+
+	/* apply forward penalty */
+	ogm_forward = (struct batadv_ogm2_packet *)skb_buff;
+	ogm_forward->throughput = htonl(neigh_ifinfo->bat_v.throughput);
+	ogm_forward->ttl--;
+
+	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+		   "Forwarding OGM2 packet on %s: throughput %u, ttl %u, received via %s\n",
+		   if_outgoing->net_dev->name, ntohl(ogm_forward->throughput),
+		   ogm_forward->ttl, if_incoming->net_dev->name);
+
+	batadv_v_ogm_queue_on_if(skb, if_outgoing);
+
+out:
+	if (orig_ifinfo)
+		batadv_orig_ifinfo_put(orig_ifinfo);
+	if (router)
+		batadv_neigh_node_put(router);
+	if (neigh_ifinfo)
+		batadv_neigh_ifinfo_put(neigh_ifinfo);
+}
+
+/**
+ * batadv_v_ogm_metric_update() - update route metric based on OGM
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ogm2: OGM2 structure
+ * @orig_node: Originator structure for which the OGM has been received
+ * @neigh_node: the neigh_node through with the OGM has been received
+ * @if_incoming: the interface where this packet was received
+ * @if_outgoing: the interface for which the packet should be considered
+ *
+ * Return:
+ *  1  if the OGM is new,
+ *  0  if it is not new but valid,
+ *  <0 on error (e.g. old OGM)
+ */
+static int batadv_v_ogm_metric_update(struct batadv_priv *bat_priv,
+				      const struct batadv_ogm2_packet *ogm2,
+				      struct batadv_orig_node *orig_node,
+				      struct batadv_neigh_node *neigh_node,
+				      struct batadv_hard_iface *if_incoming,
+				      struct batadv_hard_iface *if_outgoing)
+{
+	struct batadv_orig_ifinfo *orig_ifinfo;
+	struct batadv_neigh_ifinfo *neigh_ifinfo = NULL;
+	bool protection_started = false;
+	int ret = -EINVAL;
+	u32 path_throughput;
+	s32 seq_diff;
+
+	orig_ifinfo = batadv_orig_ifinfo_new(orig_node, if_outgoing);
+	if (!orig_ifinfo)
+		goto out;
+
+	seq_diff = ntohl(ogm2->seqno) - orig_ifinfo->last_real_seqno;
+
+	if (!hlist_empty(&orig_node->neigh_list) &&
+	    batadv_window_protected(bat_priv, seq_diff,
+				    BATADV_OGM_MAX_AGE,
+				    &orig_ifinfo->batman_seqno_reset,
+				    &protection_started)) {
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Drop packet: packet within window protection time from %pM\n",
+			   ogm2->orig);
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Last reset: %ld, %ld\n",
+			   orig_ifinfo->batman_seqno_reset, jiffies);
+		goto out;
+	}
+
+	/* drop packets with old seqnos, however accept the first packet after
+	 * a host has been rebooted.
+	 */
+	if (seq_diff < 0 && !protection_started)
+		goto out;
+
+	neigh_node->last_seen = jiffies;
+
+	orig_node->last_seen = jiffies;
+
+	orig_ifinfo->last_real_seqno = ntohl(ogm2->seqno);
+	orig_ifinfo->last_ttl = ogm2->ttl;
+
+	neigh_ifinfo = batadv_neigh_ifinfo_new(neigh_node, if_outgoing);
+	if (!neigh_ifinfo)
+		goto out;
+
+	path_throughput = batadv_v_forward_penalty(bat_priv, if_incoming,
+						   if_outgoing,
+						   ntohl(ogm2->throughput));
+	neigh_ifinfo->bat_v.throughput = path_throughput;
+	neigh_ifinfo->bat_v.last_seqno = ntohl(ogm2->seqno);
+	neigh_ifinfo->last_ttl = ogm2->ttl;
+
+	if (seq_diff > 0 || protection_started)
+		ret = 1;
+	else
+		ret = 0;
+out:
+	if (orig_ifinfo)
+		batadv_orig_ifinfo_put(orig_ifinfo);
+	if (neigh_ifinfo)
+		batadv_neigh_ifinfo_put(neigh_ifinfo);
+
+	return ret;
+}
+
+/**
+ * batadv_v_ogm_route_update() - update routes based on OGM
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ethhdr: the Ethernet header of the OGM2
+ * @ogm2: OGM2 structure
+ * @orig_node: Originator structure for which the OGM has been received
+ * @neigh_node: the neigh_node through with the OGM has been received
+ * @if_incoming: the interface where this packet was received
+ * @if_outgoing: the interface for which the packet should be considered
+ *
+ * Return: true if the packet should be forwarded, false otherwise
+ */
+static bool batadv_v_ogm_route_update(struct batadv_priv *bat_priv,
+				      const struct ethhdr *ethhdr,
+				      const struct batadv_ogm2_packet *ogm2,
+				      struct batadv_orig_node *orig_node,
+				      struct batadv_neigh_node *neigh_node,
+				      struct batadv_hard_iface *if_incoming,
+				      struct batadv_hard_iface *if_outgoing)
+{
+	struct batadv_neigh_node *router = NULL;
+	struct batadv_orig_node *orig_neigh_node;
+	struct batadv_neigh_node *orig_neigh_router = NULL;
+	struct batadv_neigh_ifinfo *router_ifinfo = NULL, *neigh_ifinfo = NULL;
+	u32 router_throughput, neigh_throughput;
+	u32 router_last_seqno;
+	u32 neigh_last_seqno;
+	s32 neigh_seq_diff;
+	bool forward = false;
+
+	orig_neigh_node = batadv_v_ogm_orig_get(bat_priv, ethhdr->h_source);
+	if (!orig_neigh_node)
+		goto out;
+
+	orig_neigh_router = batadv_orig_router_get(orig_neigh_node,
+						   if_outgoing);
+
+	/* drop packet if sender is not a direct neighbor and if we
+	 * don't route towards it
+	 */
+	router = batadv_orig_router_get(orig_node, if_outgoing);
+	if (router && router->orig_node != orig_node && !orig_neigh_router) {
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Drop packet: OGM via unknown neighbor!\n");
+		goto out;
+	}
+
+	/* Mark the OGM to be considered for forwarding, and update routes
+	 * if needed.
+	 */
+	forward = true;
+
+	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+		   "Searching and updating originator entry of received packet\n");
+
+	/* if this neighbor already is our next hop there is nothing
+	 * to change
+	 */
+	if (router == neigh_node)
+		goto out;
+
+	/* don't consider neighbours with worse throughput.
+	 * also switch route if this seqno is BATADV_V_MAX_ORIGDIFF newer than
+	 * the last received seqno from our best next hop.
+	 */
+	if (router) {
+		router_ifinfo = batadv_neigh_ifinfo_get(router, if_outgoing);
+		neigh_ifinfo = batadv_neigh_ifinfo_get(neigh_node, if_outgoing);
+
+		/* if these are not allocated, something is wrong. */
+		if (!router_ifinfo || !neigh_ifinfo)
+			goto out;
+
+		neigh_last_seqno = neigh_ifinfo->bat_v.last_seqno;
+		router_last_seqno = router_ifinfo->bat_v.last_seqno;
+		neigh_seq_diff = neigh_last_seqno - router_last_seqno;
+		router_throughput = router_ifinfo->bat_v.throughput;
+		neigh_throughput = neigh_ifinfo->bat_v.throughput;
+
+		if (neigh_seq_diff < BATADV_OGM_MAX_ORIGDIFF &&
+		    router_throughput >= neigh_throughput)
+			goto out;
+	}
+
+	batadv_update_route(bat_priv, orig_node, if_outgoing, neigh_node);
+out:
+	if (router)
+		batadv_neigh_node_put(router);
+	if (orig_neigh_router)
+		batadv_neigh_node_put(orig_neigh_router);
+	if (orig_neigh_node)
+		batadv_orig_node_put(orig_neigh_node);
+	if (router_ifinfo)
+		batadv_neigh_ifinfo_put(router_ifinfo);
+	if (neigh_ifinfo)
+		batadv_neigh_ifinfo_put(neigh_ifinfo);
+
+	return forward;
+}
+
+/**
+ * batadv_v_ogm_process_per_outif() - process a batman v OGM for an outgoing if
+ * @bat_priv: the bat priv with all the soft interface information
+ * @ethhdr: the Ethernet header of the OGM2
+ * @ogm2: OGM2 structure
+ * @orig_node: Originator structure for which the OGM has been received
+ * @neigh_node: the neigh_node through with the OGM has been received
+ * @if_incoming: the interface where this packet was received
+ * @if_outgoing: the interface for which the packet should be considered
+ */
+static void
+batadv_v_ogm_process_per_outif(struct batadv_priv *bat_priv,
+			       const struct ethhdr *ethhdr,
+			       const struct batadv_ogm2_packet *ogm2,
+			       struct batadv_orig_node *orig_node,
+			       struct batadv_neigh_node *neigh_node,
+			       struct batadv_hard_iface *if_incoming,
+			       struct batadv_hard_iface *if_outgoing)
+{
+	int seqno_age;
+	bool forward;
+
+	/* first, update the metric with according sanity checks */
+	seqno_age = batadv_v_ogm_metric_update(bat_priv, ogm2, orig_node,
+					       neigh_node, if_incoming,
+					       if_outgoing);
+
+	/* outdated sequence numbers are to be discarded */
+	if (seqno_age < 0)
+		return;
+
+	/* only unknown & newer OGMs contain TVLVs we are interested in */
+	if (seqno_age > 0 && if_outgoing == BATADV_IF_DEFAULT)
+		batadv_tvlv_containers_process(bat_priv, true, orig_node,
+					       NULL, NULL,
+					       (unsigned char *)(ogm2 + 1),
+					       ntohs(ogm2->tvlv_len));
+
+	/* if the metric update went through, update routes if needed */
+	forward = batadv_v_ogm_route_update(bat_priv, ethhdr, ogm2, orig_node,
+					    neigh_node, if_incoming,
+					    if_outgoing);
+
+	/* if the routes have been processed correctly, check and forward */
+	if (forward)
+		batadv_v_ogm_forward(bat_priv, ogm2, orig_node, neigh_node,
+				     if_incoming, if_outgoing);
+}
+
+/**
+ * batadv_v_ogm_aggr_packet() - checks if there is another OGM aggregated
+ * @buff_pos: current position in the skb
+ * @packet_len: total length of the skb
+ * @ogm2_packet: potential OGM2 in buffer
+ *
+ * Return: true if there is enough space for another OGM, false otherwise.
+ */
+static bool
+batadv_v_ogm_aggr_packet(int buff_pos, int packet_len,
+			 const struct batadv_ogm2_packet *ogm2_packet)
+{
+	int next_buff_pos = 0;
+
+	/* check if there is enough space for the header */
+	next_buff_pos += buff_pos + sizeof(*ogm2_packet);
+	if (next_buff_pos > packet_len)
+		return false;
+
+	/* check if there is enough space for the optional TVLV */
+	next_buff_pos += ntohs(ogm2_packet->tvlv_len);
+
+	return (next_buff_pos <= packet_len) &&
+	       (next_buff_pos <= BATADV_MAX_AGGREGATION_BYTES);
+}
+
+/**
+ * batadv_v_ogm_process() - process an incoming batman v OGM
+ * @skb: the skb containing the OGM
+ * @ogm_offset: offset to the OGM which should be processed (for aggregates)
+ * @if_incoming: the interface where this packet was received
+ */
+static void batadv_v_ogm_process(const struct sk_buff *skb, int ogm_offset,
+				 struct batadv_hard_iface *if_incoming)
+{
+	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
+	struct ethhdr *ethhdr;
+	struct batadv_orig_node *orig_node = NULL;
+	struct batadv_hardif_neigh_node *hardif_neigh = NULL;
+	struct batadv_neigh_node *neigh_node = NULL;
+	struct batadv_hard_iface *hard_iface;
+	struct batadv_ogm2_packet *ogm_packet;
+	u32 ogm_throughput, link_throughput, path_throughput;
+	int ret;
+
+	ethhdr = eth_hdr(skb);
+	ogm_packet = (struct batadv_ogm2_packet *)(skb->data + ogm_offset);
+
+	ogm_throughput = ntohl(ogm_packet->throughput);
+
+	batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+		   "Received OGM2 packet via NB: %pM, IF: %s [%pM] (from OG: %pM, seqno %u, throughput %u, TTL %u, V %u, tvlv_len %u)\n",
+		   ethhdr->h_source, if_incoming->net_dev->name,
+		   if_incoming->net_dev->dev_addr, ogm_packet->orig,
+		   ntohl(ogm_packet->seqno), ogm_throughput, ogm_packet->ttl,
+		   ogm_packet->version, ntohs(ogm_packet->tvlv_len));
+
+	if (batadv_is_my_mac(bat_priv, ogm_packet->orig)) {
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Drop packet: originator packet from ourself\n");
+		return;
+	}
+
+	/* If the throughput metric is 0, immediately drop the packet. No need
+	 * to create orig_node / neigh_node for an unusable route.
+	 */
+	if (ogm_throughput == 0) {
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Drop packet: originator packet with throughput metric of 0\n");
+		return;
+	}
+
+	/* require ELP packets be to received from this neighbor first */
+	hardif_neigh = batadv_hardif_neigh_get(if_incoming, ethhdr->h_source);
+	if (!hardif_neigh) {
+		batadv_dbg(BATADV_DBG_BATMAN, bat_priv,
+			   "Drop packet: OGM via unknown neighbor!\n");
+		goto out;
+	}
+
+	orig_node = batadv_v_ogm_orig_get(bat_priv, ogm_packet->orig);
+	if (!orig_node)
+		goto out;
+
+	neigh_node = batadv_neigh_node_get_or_create(orig_node, if_incoming,
+						     ethhdr->h_source);
+	if (!neigh_node)
+		goto out;
+
+	/* Update the received throughput metric to match the link
+	 * characteristic:
+	 *  - If this OGM traveled one hop so far (emitted by single hop
+	 *    neighbor) the path throughput metric equals the link throughput.
+	 *  - For OGMs traversing more than hop the path throughput metric is
+	 *    the smaller of the path throughput and the link throughput.
+	 */
+	link_throughput = ewma_throughput_read(&hardif_neigh->bat_v.throughput);
+	path_throughput = min_t(u32, link_throughput, ogm_throughput);
+	ogm_packet->throughput = htonl(path_throughput);
+
+	batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet, orig_node,
+				       neigh_node, if_incoming,
+				       BATADV_IF_DEFAULT);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(hard_iface, &batadv_hardif_list, list) {
+		if (hard_iface->if_status != BATADV_IF_ACTIVE)
+			continue;
+
+		if (hard_iface->soft_iface != bat_priv->soft_iface)
+			continue;
+
+		if (!kref_get_unless_zero(&hard_iface->refcount))
+			continue;
+
+		ret = batadv_hardif_no_broadcast(hard_iface,
+						 ogm_packet->orig,
+						 hardif_neigh->orig);
+
+		if (ret) {
+			char *type;
+
+			switch (ret) {
+			case BATADV_HARDIF_BCAST_NORECIPIENT:
+				type = "no neighbor";
+				break;
+			case BATADV_HARDIF_BCAST_DUPFWD:
+				type = "single neighbor is source";
+				break;
+			case BATADV_HARDIF_BCAST_DUPORIG:
+				type = "single neighbor is originator";
+				break;
+			default:
+				type = "unknown";
+			}
+
+			batadv_dbg(BATADV_DBG_BATMAN, bat_priv, "OGM2 packet from %pM on %s suppressed: %s\n",
+				   ogm_packet->orig, hard_iface->net_dev->name,
+				   type);
+
+			batadv_hardif_put(hard_iface);
+			continue;
+		}
+
+		batadv_v_ogm_process_per_outif(bat_priv, ethhdr, ogm_packet,
+					       orig_node, neigh_node,
+					       if_incoming, hard_iface);
+
+		batadv_hardif_put(hard_iface);
+	}
+	rcu_read_unlock();
+out:
+	if (orig_node)
+		batadv_orig_node_put(orig_node);
+	if (neigh_node)
+		batadv_neigh_node_put(neigh_node);
+	if (hardif_neigh)
+		batadv_hardif_neigh_put(hardif_neigh);
+}
+
+/**
+ * batadv_v_ogm_packet_recv() - OGM2 receiving handler
+ * @skb: the received OGM
+ * @if_incoming: the interface where this OGM has been received
+ *
+ * Return: NET_RX_SUCCESS and consume the skb on success or returns NET_RX_DROP
+ * (without freeing the skb) on failure
+ */
+int batadv_v_ogm_packet_recv(struct sk_buff *skb,
+			     struct batadv_hard_iface *if_incoming)
+{
+	struct batadv_priv *bat_priv = netdev_priv(if_incoming->soft_iface);
+	struct batadv_ogm2_packet *ogm_packet;
+	struct ethhdr *ethhdr;
+	int ogm_offset;
+	u8 *packet_pos;
+	int ret = NET_RX_DROP;
+
+	/* did we receive a OGM2 packet on an interface that does not have
+	 * B.A.T.M.A.N. V enabled ?
+	 */
+	if (strcmp(bat_priv->algo_ops->name, "BATMAN_V") != 0)
+		goto free_skb;
+
+	if (!batadv_check_management_packet(skb, if_incoming, BATADV_OGM2_HLEN))
+		goto free_skb;
+
+	ethhdr = eth_hdr(skb);
+	if (batadv_is_my_mac(bat_priv, ethhdr->h_source))
+		goto free_skb;
+
+	batadv_inc_counter(bat_priv, BATADV_CNT_MGMT_RX);
+	batadv_add_counter(bat_priv, BATADV_CNT_MGMT_RX_BYTES,
+			   skb->len + ETH_HLEN);
+
+	ogm_offset = 0;
+	ogm_packet = (struct batadv_ogm2_packet *)skb->data;
+
+	while (batadv_v_ogm_aggr_packet(ogm_offset, skb_headlen(skb),
+					ogm_packet)) {
+		batadv_v_ogm_process(skb, ogm_offset, if_incoming);
+
+		ogm_offset += BATADV_OGM2_HLEN;
+		ogm_offset += ntohs(ogm_packet->tvlv_len);
+
+		packet_pos = skb->data + ogm_offset;
+		ogm_packet = (struct batadv_ogm2_packet *)packet_pos;
+	}
+
+	ret = NET_RX_SUCCESS;
+
+free_skb:
+	if (ret == NET_RX_SUCCESS)
+		consume_skb(skb);
+	else
+		kfree_skb(skb);
+
+	return ret;
+}
+
+/**
+ * batadv_v_ogm_init() - initialise the OGM2 engine
+ * @bat_priv: the bat priv with all the soft interface information
+ *
+ * Return: 0 on success or a negative error code in case of failure
+ */
+int batadv_v_ogm_init(struct batadv_priv *bat_priv)
+{
+	struct batadv_ogm2_packet *ogm_packet;
+	unsigned char *ogm_buff;
+	u32 random_seqno;
+
+	bat_priv->bat_v.ogm_buff_len = BATADV_OGM2_HLEN;
+	ogm_buff = kzalloc(bat_priv->bat_v.ogm_buff_len, GFP_ATOMIC);
+	if (!ogm_buff)
+		return -ENOMEM;
+
+	bat_priv->bat_v.ogm_buff = ogm_buff;
+	ogm_packet = (struct batadv_ogm2_packet *)ogm_buff;
+	ogm_packet->packet_type = BATADV_OGM2;
+	ogm_packet->version = BATADV_COMPAT_VERSION;
+	ogm_packet->ttl = BATADV_TTL;
+	ogm_packet->flags = BATADV_NO_FLAGS;
+	ogm_packet->throughput = htonl(BATADV_THROUGHPUT_MAX_VALUE);
+
+	/* randomize initial seqno to avoid collision */
+	get_random_bytes(&random_seqno, sizeof(random_seqno));
+	atomic_set(&bat_priv->bat_v.ogm_seqno, random_seqno);
+	INIT_DELAYED_WORK(&bat_priv->bat_v.ogm_wq, batadv_v_ogm_send);
+
+	mutex_init(&bat_priv->bat_v.ogm_buff_mutex);
+
+	return 0;
+}
+
+/**
+ * batadv_v_ogm_free() - free OGM private resources
+ * @bat_priv: the bat priv with all the soft interface information
+ */
+void batadv_v_ogm_free(struct batadv_priv *bat_priv)
+{
+	cancel_delayed_work_sync(&bat_priv->bat_v.ogm_wq);
+
+	mutex_lock(&bat_priv->bat_v.ogm_buff_mutex);
+
+	kfree(bat_priv->bat_v.ogm_buff);
+	bat_priv->bat_v.ogm_buff = NULL;
+	bat_priv->bat_v.ogm_buff_len = 0;
+
+	mutex_unlock(&bat_priv->bat_v.ogm_buff_mutex);
+}